High electron mobility transistor

Abstract

A high electron mobility transistor (HEMT) includes a buffer layer on a substrate, a barrier layer on the buffer layer, a gate electrode on the barrier layer, a field plate adjacent to two sides of the gate electrode, and a first passivation layer adjacent to two sides of the gate electrode. Preferably, a sidewall of the field plate includes a first curve.

What is claimed is: 
     
       1. A high electron mobility transistor (HEMT), comprising:
 a buffer layer on a substrate; 
 a barrier layer on the buffer layer; 
 a gate electrode on the barrier layer; 
 a field plate adjacent to two sides of the gate electrode, wherein a top surface of the gate electrode is even with a top surface of the field plate and a sidewall of the field plate comprises a first curve; 
 a first passivation layer adjacent to two sides of the gate electrode; and 
 a p-type semiconductor layer between the gate electrode and the barrier layer and directly contacting the first passivation layer, wherein a sidewall of the p-type semiconductor layer comprises a second curve. 
 
     
     
       2. The HEMT of  claim 1 , wherein the buffer layer comprises a group III-V semiconductor. 
     
     
       3. The HEMT of  claim 2 , wherein the buffer layer comprises gallium nitride (GaN). 
     
     
       4. The HEMT of  claim 1 , wherein the barrier layer comprises Al x Ga 1-x N. 
     
     
       5. The HEMT of  claim 1 , wherein the first passivation layer comprises silicon nitride. 
     
     
       6. The HEMT of  claim 1 , further comprising a second passivation layer between the first passivation layer and the barrier layer. 
     
     
       7. The HEMT of  claim 6 , wherein the second passivation layer comprises aluminum nitride, aluminum oxide, silicon carbide, or silicon oxynitride. 
     
     
       8. The HEMT of  claim 1 , wherein the p-type semiconductor layer comprises p-type gallium nitride (p-GaN). 
     
     
       9. The HEMT of  claim 1 , wherein a bottom surface of the p-type semiconductor layer comprises a third curve. 
     
     
       10. The HEMT of  claim 1 , wherein the field plate and the gate electrode comprise a same material.